The Ecological and Evolutionary Risks of Novel GE Oilseeds to Terrestrial Organisms

THIRD WORLD NETWORK BIOSAFETY INFORMATION SERVICE

Dear Friends and Colleagues

The Ecological and Evolutionary Risks of Novel GE Oilseeds to Terrestrial Organisms

Camelina and canola oilseed crops have recently been genetically engineered to produce two novel bioactive omega-3 long-chain fatty acids (eicosapentaenoic acid, EPA and docosahexaenoic acid, DHA) which signiﬁcantly enhance the seed’s nutritional value. The purpose of these GEoilseed crops is to provide an alternate source (to wild fisheries) of EPA and DHA foraquaculture, livestock, and human consumption. They a novel type of crop because these fatty acids are not known to be naturally produced by terrestrial crop plants. A study looks at the potential ecological and evolutionary consequences of the novel production of EPA and DHA by GE oilseed crops.

The researchers raise concerns on the impacts of EPA and DHA on the biology of terrestrial invertebrates, especially if these two fatty acids become incorporated into tissues and utilized for specialized functions, such as learning behavior or ﬂight. For example, dietary EPA and DHA appear was found in a study to have negative consequences on adult metamorphosis and wing development in the cabbage white butterﬂy. Grasshoppers fed artiﬁcial diets containing EPA+DHA showed a higher growth rate and larger body size than grasshoppers fed other experimental diets without EPA+DHA, suggesting that these fatty acids are proponents of growth and development in this species which would negatively impact crop production and could lead to an increased use of insecticides. Honey bees fed ALA-deﬁcient diets had greatly reduced learning abilities in conditioning experiments. The addition of EPA and DHA in the lipid proﬁle of modiﬁed camelina proportionally reduces, by at least half, the ALA content of seed oil relative to the non-EPA+DHA seed oil. The researchers conclude that widespread introduction and persistence of EPA and DHA in the agricultural environment requires careful consideration of its effects on the ecology of terrestrial animals, especially those that participate in agricultural food webs.

The researchers warn that the physiological and downstream ecological and potential evolutionary consequences of these new terrestrial sources of EPA and DHA are largely unknown and merit critical evaluation. They call for further research and full risk and scientiﬁc assessments to be made on GE-oilseed crops prior to commercialization to understand the full scale of their potential effects on terrestrial organisms. They make recommendations such as assessing the potential for gene ﬂow of these transgenes among crops or from the crop to sexually compatible wild relatives. Because they contain molecules that have been shown to be broadly bioactive (i.e., EPA and DHA), the researchers emphasize that these GE-oilseed crops should not be classiﬁed as substantially equivalent to most commercial GE plants manufactured to date.

Two bioactive omega-3, long-chain, fatty acids (EPA and DHA), found in algal and fish oils, can now be produced in genetically engineered (GE) terrestrial oilseed crops. These fatty acids are involved in key physiological functions in invertebrates and vertebrates. They are known to be synthesized by primary producers in aquatic ecosystems, but not by terrestrial crop plants. Thus, the production of EPA and DHA by GE seed oil crops represents a fundamental shift in the accessibility of bioactive fatty acids to terrestrial consumers; one that may change their physiology and survival thereby altering ecological interactions among terrestrial organisms. Here we discuss the potential ecological and evolutionary consequences of the novel production of EPA and DHA by GE oilseed crops.

Recommendations

The physiological and downstream ecological and potential evolutionary consequences of these new terrestrial sources of EPA and DHA are largely unknown and merit critical evaluation. First, to verify the efficiency of the seed promoter, assessments of the potential for EPA and DHA synthesis in other plant tissues (vegetative, ﬂowers, nectar, and pollen) should be independently conﬁrmed. Second, the potential for gene ﬂow of these transgenes among crops or from the crop to sexually compatible wild relatives and the ﬁtness consequences of this gene ﬂow should be assessed to determine the risk that these crop-derived genes will escape cultivation. Third, experimental studies, where actual GE-plant tissues (in particular seeds, rather than artiﬁcial diets), are fed to different crop pest species (with different feeding habits) should be conducted in conﬁned and controlled conditions. Ideally, food web studies should also be conducted in order to determine the potential for unanticipated ingestion and assimilation, and subsequent downstream consequences, of EPA and DHA from seed-crop plants to herbivores and, from there, to their higher trophic level consumers. This research would provide the rigorous scientiﬁc basis required to make evidence-based regulatory and policy decisions regarding the commercialization and unconﬁned release of GE-oilseed crops producing EPA and DHA in the terrestrial environment. Full risk and scientiﬁc assessments of the suitability of these GE oil seed crops should be made, speciﬁcally including experimental trials. As transgenic crops that are non-equivalent and novel to the terrestrial ecosystem, risk assessments for both human health and the environment are needed, by national and international bodies (e.g., Codex Alimentarius, the Food and Agriculture Organization of the United Nations, and the World Health Organization). Consequently, independent, full molecular and biochemical characterization of these GE oil seed crops should be required and multi-level safety tests should be mandatory from a regulator perspective, to investigate the possible adverse effects and risks, particularly on terrestrial invertebrates and their consumers. Because they contain molecules that have been shown to be broadly bioactive (i.e., EPA and DHA), these GE-oilseed crops should not be classiﬁed as substantially equivalent to most commercial GE plants manufactured to date. Concerns within regulatory categories of risk assessments (i.e., hazard identiﬁcation, exposure, adverse effects, risk characterization), as well as documented lack of substantial equivalence (production of novel bioactive compounds) and potential identiﬁed hazards (e.g., negative effects on terrestrial insects) warrant a diligent approach. Improvement to regulatory systems needs to address the lack of well-designed GE crop monitoring frameworks (Gaef et al., 2012), particularly with GE oilseed crops that are not, in a fundamental way, equivalent to other types of commercially-available GE crops.

Conclusions

Novel, terrestrial primary production of EPA and DHA represents a major shift in the biochemistry of terrestrial ecosystems; a shift that should have positive effects on the aquaculture and livestock industries, and therefore on human nutrition. The potential beneﬁts to human health and society, environmental sustainability, and economic stability are signiﬁcant and are the key factors favoring commercialization of oilseed crops designed to produce EPA+DHA. At the same time, the novel introduction of EPA and DHA, through GE oilseeds, has the potential to cause unintended, and potentially irreversible, ecological and evolutionary consequences in terrestrial agro-ecosystems. Introducing EPA and DHA into terrestrial ecosystems may alter the physiology and ecology of land-based insect populations (and their consumers), both those considered to be crop pests, as well as those that are considered to be beneﬁcial insects. Once terrestrial crops begin producing EPA and DHA, transfer and hence retention of this unique capability within the terrestrial food web may be inevitable and irrevocable, leading to potential downstream effects that are, as yet, not understood. We suggest that further research on these GE-oilseed crops is needed prior to commercialization to understand the full scale of their potential effects on terrestrial organisms.

Two bioactive omega-3, long-chain, fatty acids (EPA and DHA), found in algal and fish oils, can now be produced in genetically engineered (GE) terrestrial oilseed crops. These fatty acids are involved in key physiological functions in invertebrates and vertebrates. They are known to be synthesized by primary producers in aquatic ecosystems, but not by terrestrial crop plants. Thus, the production of EPA and DHA by GE seed oil crops represents a fundamental shift in the accessibility of bioactive fatty acids to terrestrial consumers; one that may change their physiology and survival thereby altering ecological interactions among terrestrial organisms. Here we discuss the potential ecological and evolutionary consequences of the novel production of EPA and DHA by GE oilseed crops.

Recommendations

The physiological and downstream ecological and potential evolutionary consequences of these new terrestrial sources of EPA and DHA are largely unknown and merit critical evaluation. First, to verify the efficiency of the seed promoter, assessments of the potential for EPA and DHA synthesis in other plant tissues (vegetative, ﬂowers, nectar, and pollen) should be independently conﬁrmed. Second, the potential for gene ﬂow of these transgenes among crops or from the crop to sexually compatible wild relatives and the ﬁtness consequences of this gene ﬂow should be assessed to determine the risk that these crop-derived genes will escape cultivation. Third, experimental studies, where actual GE-plant tissues (in particular seeds, rather than artiﬁcial diets), are fed to different crop pest species (with different feeding habits) should be conducted in conﬁned and controlled conditions. Ideally, food web studies should also be conducted in order to determine the potential for unanticipated ingestion and assimilation, and subsequent downstream consequences, of EPA and DHA from seed-crop plants to herbivores and, from there, to their higher trophic level consumers. This research would provide the rigorous scientiﬁc basis required to make evidence-based regulatory and policy decisions regarding the commercialization and unconﬁned release of GE-oilseed crops producing EPA and DHA in the terrestrial environment. Full risk and scientiﬁc assessments of the suitability of these GE oil seed crops should be made, speciﬁcally including experimental trials. As transgenic crops that are non-equivalent and novel to the terrestrial ecosystem, risk assessments for both human health and the environment are needed, by national and international bodies (e.g., Codex Alimentarius, the Food and Agriculture Organization of the United Nations, and the World Health Organization). Consequently, independent, full molecular and biochemical characterization of these GE oil seed crops should be required and multi-level safety tests should be mandatory from a regulator perspective, to investigate the possible adverse effects and risks, particularly on terrestrial invertebrates and their consumers. Because they contain molecules that have been shown to be broadly bioactive (i.e., EPA and DHA), these GE-oilseed crops should not be classiﬁed as substantially equivalent to most commercial GE plants manufactured to date. Concerns within regulatory categories of risk assessments (i.e., hazard identiﬁcation, exposure, adverse effects, risk characterization), as well as documented lack of substantial equivalence (production of novel bioactive compounds) and potential identiﬁed hazards (e.g., negative effects on terrestrial insects) warrant a diligent approach. Improvement to regulatory systems needs to address the lack of well-designed GE crop monitoring frameworks (Gaef et al., 2012), particularly with GE oilseed crops that are not, in a fundamental way, equivalent to other types of commercially-available GE crops.

Conclusions

Novel, terrestrial primary production of EPA and DHA represents a major shift in the biochemistry of terrestrial ecosystems; a shift that should have positive effects on the aquaculture and livestock industries, and therefore on human nutrition. The potential beneﬁts to human health and society, environmental sustainability, and economic stability are signiﬁcant and are the key factors favoring commercialization of oilseed crops designed to produce EPA+DHA. At the same time, the novel introduction of EPA and DHA, through GE oilseeds, has the potential to cause unintended, and potentially irreversible, ecological and evolutionary consequences in terrestrial agro-ecosystems. Introducing EPA and DHA into terrestrial ecosystems may alter the physiology and ecology of land-based insect populations (and their consumers), both those considered to be crop pests, as well as those that are considered to be beneﬁcial insects. Once terrestrial crops begin producing EPA and DHA, transfer and hence retention of this unique capability within the terrestrial food web may be inevitable and irrevocable, leading to potential downstream effects that are, as yet, not understood. We suggest that further research on these GE-oilseed crops is needed prior to commercialization to understand the full scale of their potential effects on terrestrial organisms.